An indoor wireless communications system such as that disclosed in Patent Literature 1 and an optical space transmission system such as that disclosed in Patent Literature 2 are known as conventional wireless communications systems.
FIG. 12 is a schematic diagram illustrating an arrangement of the indoor wireless communications system disclosed in Patent Literature 1, which is a first conventional example.
As illustrated in FIG. 12, a signal transmitted via a master antenna 820 from a master 810 installed on a wall surface near a ceiling almost uniformly propagates via a propagation path 890 under a surface of the ceiling. Then, the signal is reflected by a secondary reflecting mirror 850 so as to propagate, via a propagation path 900, toward a floor surface. The signal is ultimately received by a slave 830, via a slave antenna 840 installed so as to have directional characteristics toward the surface of the ceiling. In the example, the secondary reflecting mirror 850 is provided so as to be rotated clockwise by approximately 45° with respect to a horizontal surface.
FIG. 13 is a schematic diagram illustrating an arrangement of a reflecting mirror used in the optical space transmission system disclosed in Patent Literature 2, which is a second conventional example.
The optical space transmission system disclosed in Patent Literature 2 also utilizes a reflecting mirror illustrated in FIG. 13, as is the case with the first conventional example. As illustrated in FIG. 13, the reflecting mirror of the second conventional example is composed of a base 310 fixed to a ceiling, and a reflecting mirror 330 rotatably attached to a shaft 320 provided on and perpendicular to the base 310. The reflecting mirror 330, which causes incident light to be subjected to a total reflection, is attached to the shaft 320 so as to be rotatable horizontally or vertically.
Citation List
Patent Literature 1
Japanese Patent Application Publication, Tokukaihei, No. 9-51293 A (Publication Date: Feb. 18, 1997)
Patent Literature 2
Japanese Patent Application Publication, Tokukaihei, No. 5-206946 A (Publication Date: Aug. 13, 1993)